Method and apparatus for making toothbrushes

ABSTRACT

A method for making toothbrushes includes the steps of, providing a toothbrush, and providing an end-rounder secured to a support. The support is substantially fixed against movement The toothbrush is moved towards the end-rounder such that free ends of bristles secured to a head of the toothbrush are rounded by the end-rounder.

FIELD OF THE INVENTION

[0001] The invention relates generally to the field of toothbrushes, andin particular to toothbrush manufacturing.

BACKGROUND OF THE INVENTION

[0002]FIG. 1 discloses a preexisting apparatus for making (finishing)toothbrushes. Pairs of toothbrushes 10 are secured to blocks 12. Thetoothbrushes are in nearly their final state of manufacture at thispoint with bristles secured to the heads of the toothbrushes. A chain 14periodically advances blocks 12 in the direction of an arrow 16.

[0003] A group of five cutters 18 are each used to trim or cut asubgroup of bristles on each brush to their specified length. A group ofseven end-rounders 20 are used to round off the cut free ends of varioussubgroups of the bristles. Chain 14 advances all of toothbrushes 10until they are properly positioned over a respective cutter orend-rounder.

[0004] A plow or fork (not shown) is then inserted into the bristles ofsome, but not all, of the toothbrushes which are adjacent to a cutter orend-rounder. The plow bends some of the bristles on a brush out of theway so that other bristles on the brush can be trimmed or end-rounded asthe case may be. A platform (support) 22 is then raised to bring thecutters and end-rounders into contact with the bristles which are to betrimmed or end-rounded. It takes about 0.75 seconds to raise all thecutters and end-rounders.

[0005] After the bristles are trimmed or end-rounded, platform 22 islowered to distance the cutters and end-rounders from the bristles.Chain 14 then advances to move the toothbrushes to the next cutter orend-rounder in the finishing process. Although not shown, after thetoothbrushes receive a final-end-rounding at the right-most end-rounderin FIG. 1, they are removed from chain 14 and packaged. Thesetoothbrushes are replaced in blocks 12 by new unfinished toothbrusheswhich have yet to be trimmed and end-rounded.

[0006] A problem with this arrangement is that during the time platform22 is being raised and lowered, no end-rounding is being done on thebristles. Further, while chain 14 is advancing the toothbrushes into andout of a certain end-rounding station, no end-rounding is being done onthe bristles. As a result, more aggressive end-rounding must be doneduring the limited time available to end-round the bristles. Thisrequires plows (forks) to be inserted into the bristles at five of theseven end-rounding stations.

SUMMARY OF THE INVENTION

[0007] The present invention is directed to overcoming one or more ofthe problems set forth above. Briefly summarized, according to oneaspect of the present invention, an apparatus for making toothbrushesincludes an end-rounder for rounding the free ends of bristles securedto a head of a toothbrush. The end-rounder is secured to a support, thesupport being substantially fixed against movement.

[0008] According to another aspect of the invention, an additionalend-rounder is included for rounding the ends of bristles secured to thehead of the toothbrush. The additional end-rounder is secured to anadditional support. The additional support is moveable alternatelytowards or away from the toothbrush to move the additional end-roundertowards or away from the toothbrush.

[0009] According to a further aspect of the invention, a cutter isprovided for trimming the length of bristles on the toothbrush headprior to the ends of these bristles being rounded by the end-rounder.The cutter is moveable alternately towards or away from the toothbrushto move the cutter towards or away from the toothbrush.

[0010] These and other aspects, objects, features and advantages of thepresent invention will be more clearly understood and appreciated from areview of the following detailed description of the preferredembodiments and appended claims, and by reference to the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is a schematic side view of a pre-existing apparatus formaking/finishing toothbrushes;

[0012]FIG. 2 is a schematic side view of an apparatus according to theinvention for making/finishing toothbrushes;

[0013]FIG. 3 is a bottom view of a bristle finishing fork inserted intoa group of bristles;

[0014]FIG. 4 is a sectional view of FIG. 3 taken along the lines 4-4 ofFIG. 3;

[0015]FIG. 5 is a sectional view of a cutter as looking into the paperon which FIG. 2 lies;

[0016]FIG. 6 is similar to FIG. 5 but also showing an end-rounder inoperating position; and

[0017]FIG. 7 is a perspective view of a bristle pattern on a toothbrushwhich can be made by the current invention.

DETAILED DESCRIPTION OF THE INVENTION

[0018] Beginning with FIG. 2, reference numerals will be used that aresimilar to the reference numerals in FIG. 1 for those elements that areessentially the same. Pairs of toothbrushes 10 are secured to blocks 12.The toothbrushes are in nearly their final state of manufacture at thispoint with tufts of bristles secured to the heads of the toothbrushes.The bristle tufts may have various heights and orientations at thispoint.

[0019] A chain 14 periodically advances blocks 12 in the direction of anarrow 16. Each advance of chain 14 takes about 0.5 seconds. The chainstops moving when a pair of toothbrushes are adjacent to each of fivecutters 18 and seven end-rounders 20(a)-(g). The cutters andend-rounders are constantly running. The bristles on each toothbrushadjacent a cutter or end-rounder are facing down towards the cutter orend-rounder.

[0020] Referring to FIGS. 3 and 4, a bristle finishing fork (or plow) 30is now inserted opposite the direction of an arrow 31 into bristles 32between head 34 of the toothbrush and a respective one of the cutters orend-rounders. The fork bends a first sub-group of bristles 36 to theside while allowing a second sub-group of bristles 38 to project througha gap 40 in the fork. This arrangement allows ends 40 of bristles 38 tobe cut or end-rounded as the case may be while preventing ends 42 ofbristles 36 from being cut or end-rounded.

[0021] Forks are used on the first three cutters the toothbrushencounters but not the last two cutters. This is the same as for theFIG. 1 apparatus. Forks are only required if it is necessary to preventsome bristles from being cut or end-rounded while other bristles are cutor end-rounded. This all depends on the final topography of the bristlesdesired.

[0022] Next, a pneumatic piston 44 is actuated to pull a piston rod 46into the piston. This causes a cam follower 48 to move along a cam path50. Cam follower 48 is also linked to a second cam follower 52 whichlikewise moves along another cam path 54. The motion of the camfollowers causes a support 56 to move up about 7 mm in about 0.6seconds. The five cutters and 1^(st) end-rounder are connected tosupport 56 and likewise move up with the support. This motion causesdesignated bristles to come into contact with the cutters andend-rounders.

[0023] Turning now to FIG. 5, the operation of the cutters will beexplained. Each cutter 18 includes four rotating trimmer blades 60 and astationary counter blade 62. The act of raising support 56 causesbristles designated for cutting to move relative to cutter 18 in thedirection of an arrow 64. After support 56 stops moving up, all of thecutters 18 are moved back and forth together in the direction ofdouble-headed arrow 64. Each movement is about 2.5 inches and thecutters make about 5 cycles back and forth. This movement of the cuttersallows the designated bristles of both toothbrushes presented to eachcutter to be properly trimmed. The cutting operation takes about 4seconds. The orientation and/or position of a cutter can be adjusted toalter the angle of cut on the bristles.

[0024] Referring to FIG. 6, end-rounder 20(a) is also raised on support56. End rounder 20(a) includes a partial spherical surface 66 which hasa roughened finish for abrading and rounding the free ends of bristles38. The end-rounder is rotated in the direction of an arrow 68 about anaxis 70. Axis 70 is also rotated about axes 72 and 74. The resultantmotion results in what is called an orbital end-rounder. Further detailson this type of end-rounder and on fork 30 can be found in U.S. Pat. No.5,593,213.

[0025] The remaining end-rounders 20(b)-(g) are not connected to support56 and so do not move up or down with the support. Each end rounder20(b)-(g) is connected to an additional support 76 which issubstantially fixed against movement. As such, these six end-roundersare already in position to end-round when chain 14 starts moving thetoothbrushes. After end-rounding and cutting is complete, piston 44 isactuated to lower support 56 and thus lower the five cutters and thefirst end-rounder. This lowering operation takes about 0.5 seconds.

[0026] Although not shown, after the toothbrushes receive afinal-end-rounding at the right-most end-rounder 20(g), they are removedfrom chain 14 and packaged. These toothbrushes are replaced in blocks 12by new unfinished toothbrushes which have yet to be trimmed andend-rounded.

[0027] There are a number of advantages to thus fixing the last sixend-rounders in position. End-rounding can now be done while chain 14 ismoving toothbrushes both into and out of a particular end-rounder, aswell as during substantially all of the time support 56 is being raisedand lowered. This adds about 1.5 more seconds of end rounding for eachtoothbrush at each of the six fixed end-rounders. Thus about nine moreseconds of end-rounding are done on each brush. This additionalend-rounding times allows end-rounding to be done less aggressively. Asa result, none of end-rounders (b)-(g) require forks 30 to be used,resulting in a cost savings. In the system of FIG. 1, four of these sixend-rounders required forks to be used. End-rounder 20(a) still requiresa fork because it is end-rounding the shortest bristles on thetoothbrush.

[0028] Another advantage is that support 56 can be raised faster becauseit is lifting only one end-rounder instead of seven end-rounders. As aresult, support 56 can be raised in about 0.2 seconds.

[0029]FIG. 7 shows a toothbrush 80 which can be made by the method andapparatus described above. The bristle pattern is that of the Advantage®toothbrush sold by Oral-B®. Toothbrush 80 includes a head 82 from whichextends a group of bristle tufts 84 known as a “power tip”. The topsurface of tufts 84 angles down towards head 82. Another group ofbristle tufts 86define a “V” or “U” shaped grove 88 known as an “actioncup”.

[0030] The invention has been described with reference to a preferredembodiment. However, it will be appreciated that variations andmodifications can be effected by a person of ordinary skill in the artwithout departing from the scope of the invention.

1. An apparatus for making toothbrushes, comprising: an end-rounder forrounding the free ends of bristles secured to a head of a toothbrush;and a support to which the end-rounder is secured, the support beingsubstantially fixed against movement.
 2. The apparatus of claim 1,further comprising: an additional end-rounder for rounding the ends ofbristles secured to the head of the toothbrush; and an additionalsupport to which the additional end-rounder is secured, the additionalsupport being moveable alternately towards or away from the toothbrushto move the additional end-rounder towards or away from the toothbrush.3. The apparatus of claim 2, further comprising: means for moving theadditional support towards or away from the toothbrush.
 4. The apparatusof claim 1, further comprising: a cutter for trimming the length ofbristles on the toothbrush head prior to the ends of these bristlesbeing rounded by the end-rounder, the cutter being moveable alternatelytowards or away from the toothbrush to move the cutter towards or awayfrom the toothbrush.
 5. The apparatus of claim 4, further comprising: anadditional end-rounder for rounding the ends of bristles secured to thehead of the toothbrush; and an additional support to which theadditional end-rounder is secured, the additional support being moveablealternately towards or away from the toothbrush to move the additionalend-rounder towards or away from the toothbrush, the cutter beingsecured to the additional support such that it moves with the additionalend-rounder.
 6. A method for making toothbrushes, comprising the stepsof: providing a toothbrush; providing an end-rounder secured to asupport, the support being substantially fixed against movement; andmoving the toothbrush towards the end-rounder such that free ends ofbristles secured to a head of the toothbrush are rounded by theend-rounder.
 7. The method of claim 6, comprising the further steps of:providing an additional end-rounder for rounding the ends of bristlessecured to the head of the toothbrush; providing an additional supportto which the additional end-rounder is secured; moving the additionalsupport towards the toothbrush such that free ends of bristles securedto the head of the toothbrush are rounded by the end-rounder.
 8. Themethod of claim 7, comprising the further step of: moving the additionalend-rounder away from the toothbrush to disengage the bristle ends fromthe end-rounder.
 9. The method of claim 6, comprising the further stepof: moving a cutter towards the bristles.
 10. The method of claim 9,comprising the further step of: trimming the length of bristles on thetoothbrush head with the cutter prior to the ends of these bristlesbeing rounded by the end-rounder.
 11. The method of claim 10, comprisingthe further step of: moving the cutter away from the bristles.
 12. Themethod of claim 11, further comprising the step of: providing anadditional end-rounder for rounding the ends of bristles secured to thehead of the toothbrush.
 13. The method of claim 12, further comprisingthe step of: providing an additional support to which the additionalend-rounder is secured.
 14. The method of claim 13, further comprisingthe step of: moving the additional support alternately towards or awayfrom the toothbrush to move the additional end-rounder towards or awayfrom the toothbrush.
 15. The method of claim 14, further comprising thestep of: securing the cutter to the additional support such that thecutter moves with the additional end-rounder.